Introduction: The World Health Organization on March 11, 2020 declared the outbreak of severe acute respiratory syndrome Corona virus 2 disease (COVID-19) a pandemic situation. The main aim of this study was investigating mortality of COVID 19 by considering chronic diseases. Materials and methods: this study was conducted as a cross-sectional in which all confirmed cases were examined. The variables considered in this study were age, sex, diabetes mellitus, cancers, hypertension, heart diseases, kidney diseases, and liver diseases. Independent sample t test, Chi-square and binary logistic regression were used to data analysis. All statistical analysis was done in SPSS 16 and significant level was set at 0. 05. Results: Out of 22849 PCR and CT scan tests, 16061 ones were positive. According to the confirmed cases, prevalence of COVID-19 was calculated about 0. 019. Also hospital case fatality rate and mortality rate were calculated 156 and about 8. 2 per 100000 respectively. Hypertension, and age had significant relationship with morbidity of COVID-19, in other hand, age (OR: 4. 51, p<0. 001), kidney diseases (OR: 1. 84, p<0. 001), diabetes mellitus (OR: 1. 31, p<0. 001), cancer (OR: 2. 73, p<0. 001), liver diseases (OR: 2. 27, p<0. 001) had impact on mortality of covid-19. Population Attributable Fraction (PAF) showed that diabetes mellitus, cancers, kidney diseases, and liver diseases had 4. 2, 2. 4, 1. 3, and 0. 2 percent, respectively. Conclusion: age and some underlying diseases increase odds of death due to COVID-19. It seems that preventing high-risk people from being infected is an effective solution to reduce COVID-19 death rate. To do this, health protocols need to be implemented more seriously for these sensitive groups.